Chandrayan 2

SPACE TECHNOLOGY

Our Remote Sensing Lunar Satellite Is All Alive

Every Indian will have a moment to reminisce when he hears the term ‘Moon’. Moon is something, we always admired and included in our paintings, poems, tales, etc. Moon has been serving as one of the popular metaphors all over the world to signify beauty and purity, for ages now. But, the real facts about Moon are remaining to be a mystery till date.

Probably between December 1609 and January 1610,Galileo Galilei

discovered some objects in the space and recognized it as the satellites of Jupiter in March 1610. The Galilean Moons are four large moons namely Lo, Europa, Ganymede and Calisto. These are the known largest moons in our solar system. Later, after seeking many strenuous developments, finally Soviet Union decided to send their first spacecraft, Luna 2 in the year 1959 to know more about our Moon. Soon, in the year 1969, America sent Commander

After China, Indian Space Research Organization decided to work on a new project to contribute India's knowledge for the study of lunar world.

Neil Armstrong accompanied by Lunar Pilot Buzz Aldrin to land on Moon with their ApolloLunar Module Eagle spacecraft and made an indelible history. After Soviet Union and America, China entered the field and it carried its own success stories. After China, Indian Space Research Organization decided to work on a new project to contribute India's knowledge for the study of lunar world. Since then all the supremely dexterous Indian hands joined together in 2008 to take up a mission of flagging up

our Tricolor national flag on the lunar ground. The mission was named as Chandrayaan, meaning Moon Vehicle in Sanskrit.

Chandrayaan-1 released its Moon Impact Probe that took control over the south lunar pole on November 14, 2008 and made India as the fourth ever country to leave its unflinching mark on the Lunar ground. The probe hit the part near the crater Shackleton and ousted some handheld amount of sub-surface soil that helped scientists to discover the presence of Lunar Water Ice on the lunar grounds. The location of this impact was taken control by Indian Space Research Center and proudly named the part as "Jawahar Point". Chandrayaan-1 turned out to be one of the significant sources to understand and appreciate Moon. This progress gave Indian scientists a greater view of the lunar system and leveled up their vision.As a result of this consequential success, Indian scientists' confidence and perspicacious outlook employed substantial intention of discovering more of our Moon. ISRO has made its first autochthonous integral

parts like lunar orbiter, lander named as Vikram and rover named as Pragyan to make the mission possible.On 22 July 2019, a geosynchronous satellite launch vehicle lifted-off from Satish Dhawan Space Centre into skies at 2:43 pm. ISRO Chief K Sivan along with his fellow scientists watched the launch sequence in rapt attention. 16 minutes later, India's second lunar mission the 3,850 kg Chandrayaan-2 was successfully placed into the earth's orbit.

Chandrayaan-2 is expected to reach the moon by August 20, this year. The rocket used to fire the satellite by ISRO is Geosynchronous Satellite Launch Vehicle Mark-III-M1 (GSLV MkIII-M1) in Sriharikota Island, Andhra Pradesh.

The vehicle has been nicknamed ISRO's Baahubali by Telugu media, for its capacity to carry a payload of up to four tonnes. Apart from the lunar orbiter, the launcher carries a lander Vikram, named after Dr.Vikram Sarabhai, the father of the

The Rs 978/- crore mission will make India the fourth country to have landed a rover on the moon after US, Russia and China. After a 48 day journey to the celestial body, Chandrayaan-2 will explore the uncharted South Pole, a 'giant leap' for the Nation. The mission also carries a total of 13 payloads, which includes three from Europe, two from America and one from Bulgaria, which seeks to improve the understanding of the moon. GSLV Mk-III rocket will carry the Indian made equipment and fly. Chandrayaan-2’s initial launch was scheduled on 15 July but was put off due to a technical glitch. Now

Indian space programme. Inside Vikram is a rover called Pragyan, meaning wisdom in Sanskrit. Chandrayaan-2 was built from U R Rao satellite Centre, Bangaluru. After Chandrayaan-1 crashed into the moon's surface, the second of the series was built for a soft landing. A Laser Retro reflector Array (LRA) of NASA is among the payloads and is aimed to understand the dynamics of the earth’s moon system.The main parts of the satellite are an orbiter of 379 kg with eight payloads, a lander with working power of one lunar period of time, and a rover named Pragyan. GSLV Mk-III-M1 is

10 August 2019 Executive Knowledge Lines

assigned to take the lunar module into orbit around the earth, once launched into space. The module released from the rocket circles the earth multiple times, using the earth's gravitational force to gain momentum as re-orienting the moon. The moon's gravitational pull holds while spinning out of earth's orbit. To stay in the moon's gravitational field, the onboard thrusters help by slowing it down. Before Vikram detaches from the orbiter, it is designed to circle the moon. Vikram has to take a different trajectory, circling closer and closer to the moon to find a landing site. Then, in 15 fraught minutes, Vikram lands on the moon. Meanwhile, Lander slowdowns, braking against the moon's gravitational pull. This requires the firing of a propulsion engine, which in turn will cause lunar dust to fly at it. The sharp and jugged lunar dust having a negative charge helps to cling on to the moon's surface, disrupting solar panels and sensors. This means the possibility of losing touch with the control station. But the successful landing of Vikram writes a big milestone in Indian space history.

The door of Vikram not only opens the way to Pragyan but also to a new era in Indian space research. Pragyan takes four hours to descend down the ramp that Vikram lowers, and roll onto the moon. But the dream will come true only when the door stays without damage after the landing. Pragyan can move at the speed of 1 cm/s and can travel up to half a kilometre away from Vikram. It investigates through the surface of the moon for one lunar day (16 earth days). The collected information transmitted to Vikram from where it finds the way to earth. Pragyan carries a range of spectrometers (apparatus used to calculate the composition of materials by passing radiation). As Chandrayaan-1 detected the presence of water molecules, Pragyan looks for more traces.

An advanced synthetic aperture radar for this purpose it carries an advanced synthetic aperture radar. The radar is used to test the presence of water through several metres of rocks. If the moon is proven to have sufficient water reserves, the moon sustaining human life in future is not far. The orbiter circles the moon for a year at 100-km orbit. The payloads in the orbiter range from highresolution cameras to a spectrometer, to measure the moon's atmospheric composition.

Moon’s South Pole remains in the dark as it receives very little sunlight; hence its secrets are left uncovered. Some part is permanently under the shade, because of the tilt of the moon's axis. The flabbergasting surface also contains 'cold traps', down the giant craters. This region can freeze liquid as well as a range of volatile compounds. The temperature can low as -200-degree Celsius. But this information triggers the anxiety of most scientists. Because the compounds in these cold traps have been possibly frozen for a time of three billion years! So the chance of finding the records of early Solar System is on board. Any findings may contribute to theories on 'birth of moon'.

The most complex mission ever undertaken by the ISRO has another pride to carry with. Chandrayaan-2 is the first interplanetary to be steered by women, project director Vanitha Muthayya and mission director Ritu Kridhal. And among the 300 scientists behind Chandrayaan 30 per cent are women. If all the assigned series of maneuvers undergoes well, if Vikram can pull it off, it will be a triumph of indigenous science. When the world along with NASA celebrates 50 years of the 'First landmark', India is ready to take billion dreams to the moon.

August 2019